This invention relates to a Fischer-Tropsch reaction. More particularly, this invention relates to a process for the selective conversion of synthesis gas to dimethyl ether and methanol by continuously passing a feed stream of carbon monoxide and hydrogen over a supported rhodium-molybdenum catalyst at reaction conditions correlated to produce such products.
It is known in the art to react carbon monoxide and hydrogen to produce dimethyl ether and methanol. For example, U.S. Pat. No. 3,941,819 discloses a process for the production of substantial amounts of dimethyl ether by passing carbon monoxide and hydrogen over platinum supported on alumina at a temperature ranging from 100.degree. C. to 400.degree. C. and a pressure ranging from 1 to 100 atmospheres. U.S. Pat. No. 4,098,809 discloses that dimethyl ether can be prepared by feeding a mixture of CO, CO.sub.2 and H.sub.2, wherein the quantity of CO is in excess of the stoichiometric value, to a reactor containing a methyl alcohol synthesis catalyst, such as a copper base or chrome-zinc base catalyst, a methyl alcohol dehydration catalyst, such as alumina, whereby methyl alcohol is formed as an intermediate product which is transformed into dimethyl ether in the same reactor at a temperature in the range of 220.degree. C. to 400.degree. C. and a pressure in the range of 30 to 500 kg/cm.sup.2. The hydrogenation of carbon monoxide over supported palladium catalysts to yield methanol in high selectivity is reported by Poutsma et al., "J. Catalysis," vol. 52, (1978), pp. 157-160. In a recently published study by Bhasin et al., "J. Catalysis," vol. 54, (1978), p. 120, there is reported the formation of methanol in large amounts when synthesis gas is contacted with a rhodium-iron catalyst.